firmware/target/arm/as3525/dma-pl081.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright © 2008 Rafaël Carré
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 #include <stdbool.h>
  23 #include "as3525.h"
  24 #include "pl081.h"
  25 #include "dma-target.h"
  26 #include "panic.h"
  27
  28 static int dma_used = 0;
  29 static void (*dma_callback[2])(void); /* 2 channels */
  30
  31 void dma_retain(void)
  32 {
  33     if(++dma_used == 1)
  34     {
  35         CGU_PERI |= CGU_DMA_CLOCK_ENABLE;
  36         DMAC_CONFIGURATION |= (1<<0);
  37     }
  38 }
  39
  40 void dma_release(void)
  41 {
  42     if(--dma_used == 0)
  43     {
  44         DMAC_CONFIGURATION &= ~(1<<0);
  45         CGU_PERI &= ~CGU_DMA_CLOCK_ENABLE;
  46     }
  47 }
  48
  49 void dma_init(void)
  50 {
  51     DMAC_SYNC = 0xffff; /* disable synchronisation logic */
  52     VIC_INT_ENABLE |= INTERRUPT_DMAC;
  53 }
  54
  55 inline void dma_disable_channel(int channel)
  56 {
  57     DMAC_CH_CONFIGURATION(channel) &= ~(1<<0);
  58 }
  59
  60 void dma_enable_channel(int channel, void *src, void *dst, int peri,
  61                         int flow_controller, bool src_inc, bool dst_inc,
  62                         size_t size, int nwords, void (*callback)(void))
  63 {
  64     dma_callback[channel] = callback;
  65
  66     int control = 0;
  67
  68     DMAC_CH_SRC_ADDR(channel) = (int)src;
  69     DMAC_CH_DST_ADDR(channel) = (int)dst;
  70
  71     DMAC_CH_LLI(channel) = 0;    /* we use contigous memory, so don't use the LLI */
  72
  73     /* specify address increment */
  74     if(src_inc)
  75         control |= (1<<26);
  76
  77     if(dst_inc)
  78         control |= (1<<27);
  79
  80     /* OF use transfers of 4 * 32 bits words on memory, i2sin, i2sout */
  81     /* OF use transfers of 8 * 32 bits words on SD */
  82
  83     control |= (2<<21) | (2<<18);  /* dst/src width = word, 32bit */
  84     control |= (nwords<<15) | (nwords<<12);  /* dst/src size  */
  85     control |= (size & 0x7ff);     /* transfer size */
  86
  87     control |= (1<<31); /* current LLI is expected to trigger terminal count interrupt */
  88
  89     DMAC_CH_CONTROL(channel) = control;
  90
  91     /* we set the same peripheral as source and destination because we always
  92      * use memory-to-peripheral or peripheral-to-memory transfers */
  93     DMAC_CH_CONFIGURATION(channel) =
  94         (flow_controller<<11)   /* flow controller is peripheral */
  95         | (1<<15)               /* terminal count interrupt mask */
  96         | (1<<14)               /* interrupt error mask */
  97         | (peri<<6)             /* dst peripheral */
  98         | (peri<<1)             /* src peripheral */
  99         | (1<<0)                /* enable channel */
 100         ;
 101 }
 102
 103 /* isr */
 104 void INT_DMAC(void)
 105 {
 106     unsigned int channel;
 107
 108     /* SD channel is serviced first */
 109     for(channel = 0; channel < 2; channel++)
 110         if(DMAC_INT_STATUS & (1<<channel))
 111         {
 112             if(DMAC_INT_ERROR_STATUS & (1<<channel))
 113                 panicf("DMA error, channel %d", channel);
 114
 115             /* clear terminal count interrupt */
 116             DMAC_INT_TC_CLEAR = (1<<channel);
 117
 118             if(dma_callback[channel])
 119                 dma_callback[channel]();
 120         }
 121 }